Sharawat Indar Kumar, Saini Lokesh, Singanamala Bhanudeep, Saini Arushi Gahlot, Sahu Jitendra Kumar, Attri Savita Verma, Sankhyan Naveen
Pediatric Neurology Division, Department of Pediatrics, All India Institute of Medical Sciences, Rishikesh, Uttarakhand 249201, India.
Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Brain Dev. 2020 Feb;42(2):157-164. doi: 10.1016/j.braindev.2019.11.003. Epub 2019 Dec 2.
Isolated sulfite oxidase deficiency (ISOD) is a rare autosomal recessively inherited inborn error of metabolism, caused by mutation in SUOX gene. ISOD has two kind of presentation; early and late-onset. The late-onset form is extremely rare and only 10 cases have been reported.
We report two new cases of late-onset ISOD with biochemical and genetic confirmation. We did a review of the previously published cases of late-onset ISOD.
Together with the presented two cases, 12 cases were available for analysis. The median age at symptom onset and at diagnosis was 8.5 and 23 months respectively. Almost all children had acute regression of milestones followed by slow recovery. The common presenting signs and symptoms were movement disorders, seizures, ectopia lentis and hypertonia. Five children had antecedent events. Trivial trauma precipitating the metabolic crisis was unique to the two cases we report. The most common MRI feature was globus pallidi changes followed by cerebellar white matter changes, vermian hypoplasia and thinned out corpus callosum. Diffusion weighted sequence was performed in 3 children and all had diffusion restriction in the affected area.
Trivial trauma can precipitate metabolic crisis in late-onset ISOD. Low plasma homocysteine and involvement of globus pallidi with diffusion restriction on the MRI are important diagnostic clues. Early diagnosis and intervention with special diet may be effective in preventing long term neurodisability.
孤立性亚硫酸盐氧化酶缺乏症（ISOD）是一种罕见的常染色体隐性遗传代谢性先天性疾病，由SUOX基因突变引起。ISOD有两种表现形式：早发型和晚发型。晚发型极为罕见，仅报道过10例。
我们报告两例经生化和基因确诊的晚发型ISOD新病例。我们对先前发表的晚发型ISOD病例进行了回顾。
连同所呈现的两例病例，共有12例可供分析。症状出现和诊断时的中位年龄分别为8.5个月和23个月。几乎所有儿童都出现发育里程碑的急性倒退，随后缓慢恢复。常见的症状和体征包括运动障碍、癫痫发作、晶状体异位和张力亢进。5名儿童有前驱事件。轻微创伤引发代谢危机是我们报告的两例病例所特有的。最常见的MRI特征是苍白球改变，其次是小脑白质改变、蚓部发育不全和胼胝体变薄。3名儿童进行了扩散加权序列检查，所有患儿在受累区域均有扩散受限。
轻微创伤可引发晚发型ISOD的代谢危机。低血浆同型半胱氨酸以及MRI上苍白球受累伴扩散受限是重要的诊断线索。早期诊断并采用特殊饮食进行干预可能有效预防长期神经残疾。
